Toxic gas monitoring systems are well known. Generally, gas monitors are placed around chemical producing facilities such as a chemical processing or hydrocarbon producing plants. These monitoring systems are configured to monitor for the presence of toxic and/or combustible chemicals. In addition to monitoring for the presence these chemicals, typically in parts per million or lower explosive limits, these detectors can also detect other important information, such as wind speed and direction, temperature and other weather conditions. This information is then relayed to some sort of output system. For instance, the information can be relayed back to the control center of a chemical plant and be displayed on a computer terminal or be comprised in a computer printout.
In U.S. Pat. No. 3,068,692, a meteorological telemetering device detects wind direction and speed. The device utilizes pairs of light sources and photocells that are aligned with each other and represent various points of the compass. A first disk coupled for rotation with a wind vane has a shaped window of width varying in accordance with a selected mathematical relationship, and a second disk including a plurality of spiraling slots is coupled for rotation to and anemometer. The two disks are free to rotate under the control of their moving elements and interrupt light reaching the four photocells, as determined by the first disk and the speed of the second disk. With proper positioning and dimensioning of the apertures in the first and second disks, one or two of the photocells will be energized for any given wind direction, and the energized photocells will receive pulses of light. The total number of pulses is a function of the wind velocity, and the distribution of pulses between the one or two energized photocells is a function of wind direction. The four photocells are connected through time controlled gates to decade counters, so that the “X” and “Y”, components of wind speed and direction are recorded or stored for transmission to a central recording station. Although the device provides wind direction and velocity, it does not provide any gas sensing capabilities. Further, the technique used to determine wind direction is complex, since it is based on mathematical formulas associated with the complex shape of the window in the first disk.
In U.S. Pat. No. 3,708,566, a device is disclosed for continuously sampling the atmosphere in the direction of the wind to monitor, detect, measure and record the amount of a given constituent in the atmosphere by providing a plurality of conduits each having an inline valve in a normally closed position. The conduits and valves are associated with a wind direction. A particular valve in a conduit is opened in response to a wind detector identifying wind direction and sending a signal to open a corresponding valve in the conduit. Once a valve is open, air enters the conduit and flows to an air sample analyzer, where the constituents in the air sample can be determined. Although the device detects direction of wind and samples the air corresponding to, the direction of the wind, the device requires mechanical parts, such as the valves and conduits, and does not provide any warning or alarm conditions in the event of harmful chemicals found in the air.
In U.S. Pat. No. 6,252,510, a wireless toxic gas monitoring system is disclosed. The system implements multiple toxic gas monitors (detectors) that are placed around a plant and transmits information, such as type of gas, wind direction and wind speed, via a wireless medium to a receiver at a central control station. Although the system provides for an array of gas monitoring detectors to be located around a plant, the gas monitoring detectors are complex in terms of electro-mechanical components. In particular, each gas monitoring detector utilizes a microprocessor for running application programs, user interfaces (e.g., a display panel, keyboard, and the like), a power supply, among other components, which are costly to set up and implement in terms of maintenance and labor to operate.
Accordingly, there is a need in the art for a simplified, yet improved gas and wind detection system capable of detecting harmful gases in the environment and the direction of the wind, and providing an early-warning system to alert personnel in the vicinity of such dangerous conditions. Further, there is a need to provide the early-warning detection system in a manner that alerts personnel so that they can retreat away from the path of the oncoming harmful gases. Moreover, there is a need to implement a gas alarm and wind indicator system that is highly reliable in terms of the components used and that can be constructed and operated in a cost effective manner.